Sn-based Hydroxide Of Regulating The Preparation And Photocatalytic Of Benzene

A series of MSn(OH)6(MHS, M=Co, Cu, Fe, Mg, Mn, Zn) was synthesizedby a hydrothermal method in this work. The effects of the hydrothermal temperature, timeand the solution pH on the formation of MHS were investigated. on the prepared MHS wasinvestigated and compared with P25(TiO2). The results indicate the optimal preparationcondition of MHS is performing the hydrothermal treatment at a mild temperature(90–120oC) in a weak base solution (pH10–11). The structures, yields, optical properties,and morphologies of the products were then studied. Only MgHS and ZnHS exhibit asignificant and stable activity for the destruction of C6H6and the efficiencies aresubstantially higher than that of P25. The hydroxyl structure accounts for their highperformance, which facilitates the formation of the active radicals (O2-· and·OH) andsuppresses the deposition of the stable byproducts. Due to the restriction of the bandstructures, the degradation of C6H6cannot be achieved on the colored samples (M=Co,Cu, Fe, and Mn). Based on the radicals analyses results, the degradation route of C6H6onand the formation route of the stable intermediates on the samples were finallyproposed.All of MSn(OH)6catalysts by hydrothermal method synthesis,selecting goodactivity and stability catalyst ZHS to do further reseach.It is indispensable to find a suitablepreparation method to optimize the photocatalyst performance. Different ZnSn(OH)6(ZHS)were prepared by four methods in this report, including grinding, co-precipitation,self-templating, and hydrothermal processes. Photocatalytic degradation of methyl orange(MO) and gaseous benzene (C6H6) over the samples were assessed and compared. Therelationship between the microstructure and the photocatalytic performance of ZHS wasanalyzed. The results reveal the surface microstructure and the photocatalytic performanceof ZHS are more sensitive to the preparation methods than the crystal structure and themorphology. A harsh preparation condition leads to the formation of some OH-unsaturatedZn and Sn atoms due to the susceptible of OH groups, which result in a tail light absorptionof ZHS and are assumed as the photoactive center. ZHS prepared by the PVP-assistedhydrothermal method exhibits the highest thermal stability, optical absorption, BET surface area and ability for ZnSn(OH)6activation, and consequently shows the highestphotocatalytic activity and stability for the degradation of MO and gaseous C6H6.